Image created by Dr. Michael J. Miller
Developed by engineers at the University of Bath, the prototype LoCKAmp device uses innovative Lab-on-a-Chip technology and has been proven to provide rapid and low-cost detection of COVID-19 from nasal swabs. The research team said the technology could easily be adapted to detect other pathogens such as bacteria — or even conditions like cancer.
The device works by rapidly releasing and amplifying genetic material from a nasal swab sample by carrying out a chemical reaction to produce a result, which can be viewed on a smartphone app.
Made with off-the-shelf components and factory-manufactured printed circuit boards, the prototype device could be made on a mass scale quickly and at low cost, presenting care providers and public health bodies around the world with an effective new tool in virus detection. The research team said a commercial partner with the relevant design and manufacturing expertise could quickly redesign the LoCKAmp into a small, portable device — with great potential for use in remote healthcare settings.
“We started researching and developing LoCKAmp during the second wave of COVID in the U.K.,” said Research Lead Dr. Despina Moschou. “We were confident we could create a portable, lowcost device that could carry out genetic identification of the virus, like a PCR test, within 10 minutes. We have done that but found it can actually work within just three minutes.”
The testing unit is projected to cost as little as £50 (about $62) when it reaches mass production, while the test cartridges, currently made for £2.50 ($3.10), could cost less than 50 pence ($.62).
LoCKAmp harnesses a process known as RT-LAMP (reverse transcription loop-mediated isothermal amplification) to multiply specific sequences of RNA, meaning it can quickly detect a particular virus. The team says LAMP detection is preferable to PCR testing as it has higher sensitivity, is faster, and more specific.
Crucially, processing takes place at a single stable temperature of 65 °C, instead of needing the three thermal cycles a PCR test requires. This means the device can be made easier at a portable size, and with lower power consumption. A further benefit of the design is that no pre-processing of the nasal swab samples is required.
Once a nasal swab sample is added to the device, the LoCKAmp pumps the liquid through tiny transparent ‘microfluidic’ channels layered onto the circuit board, above copper heaters just 0.017- mm thick. These heat the sample, releasing the RNA genetic material from the virus. This is then further heated and treated with RT-LAMP chemicals to encourage multiplication.
If the specific virus RNA is present in the amplified sample, it fluoresces under light — this signal is then used to denote a positive test.
The device was tested with COVID-19 patient swabs collected by Bath’s Royal United Hospital Trusts during the third wave of the pandemic.
As well as proving the system’s capability in analyzing nasal swab samples, the LoCKAmp could also be used to carry out anonymized community-level monitoring and detection of viruses like COVID-19 by testing wastewater.
“With LoCKAmp technology providing both low-cost and real-time genetic target identification and quantification, we’re getting ever closer to real-time pathogen tracking,” said Professor Barbara Kasprzyk-Hordern. “This opens exciting opportunities enabling the establishment of early warning systems utilizing wastewater for pathogen surveillance in communities.”